Due to popularization of the Internet, it has been demanded to ensure the accessibility to information networks at many locations in building structures such as general houses and office buildings. For example, Japanese Patent Early Publication [kokai] No. 11-187154 discloses a multimedia g system having a distribution board for controlling an electric power line and various kinds of signal lines installed in a structure in a centralized control manner, and a multimedia receptacle panel, which is adapted in use to be mounted in an indoor wall surface, and connected to the distribution panel through the electric power line and the signal lines. For example, the multimedia receptacle panel has a power receptacle for supplying commercial electric power to an electric appliance, receptacle for receiving broadcasting programs such as ground wave broadcasting, satellite broadcasting, and cable television, modular jacks for analog and digital lines used for the Internet and telephone communication. By use of this multimedia wiring system, the convenience of multimedia products is enhanced to obtain comfortable living and working environments in the information society.
By the way, the above-described multimedia receptacle panel is usually mounted in the wall surface, and connected to the electric power line and the signal lines under construction works of the building structures. This means that the functions of the multimedia receptacle panel are determined at the time of the construction works. Therefore, after the construction works are finished, it is difficult to add a new function to the multimedia receptacle panel or exchange a part of the functions of the existing multimedia receptacle panel for another function. In addition, when exchanging the existing multimedia receptacle panel for another multimedia panel, a repair work is needed. However, such a repair work is not easy for general users to perform, and the costs of the repair work become a burden to the user.
Thus, the conventional multimedia receptacle panel still has plenty of room for improvement from the viewpoints of easy exchangeability and function expandability.